11.   They recall previous U.S. invasions of Panama and Grenada, when the safety of Americans became the justification for sending in the troops.

12.   Tunnel safety has become a major issue in Europe in recent years.

13.   Typically, prosecutors do so when public safety becomes a concern during the course of the investigation.

14.   With the Hyatt, building safety became a greater priority.

15.   Air travel safety has become an emotional issue for many in Taiwan and China, which between them have suffered three fatal air crashes the past two months.

16.   But a series of factory disasters in China, plus the Thailand tragedy, have aroused fears that worker safety has become a casualty of rapid economic growth.

17.   Now, with Amtrak pushing to introduce high-speed trains in densely populated areas, grade-crossing safety has become a more pressing issue.

18.   Since those deaths, safety has become a major issue, with a debate over possible rules changes and the use of new safety equipment.

19.   The fear is that unless the government injects proper funding into the Tube, safety could become at risk.